System for the three-dimensional display of wireless communication system performance

ABSTRACT

A method for displaying the results of predicted wireless communication system performance as a three-dimensional region of fluctuating elevation and/or color within a three-dimensional computer drawing database consisting of one or more multi-level buildings, terrain, flora, and additional static and dynamic obstacles (e.g., automobiles, people, filing cabinets, etc.). The method combines computerized organization, database fusion, and site-specific performance prediction models. The method enables a design engineer to visualize the performance of any wireless communication system as a three-dimensional region of fluctuating elevation, color, or other aesthetic characteristics with fully selectable display parameters, overlaid with the three-dimensional site-specific computer model for which the performance prediction was carried out.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to co-pending applications having Ser. Nos.09/221,985, filed Dec. 29, 1998 (now U.S. Pat. No. 6,442,507), Ser. No.09/318,840, filed May 26, 1999 (now U.S. Pat. No. 6,317,599), Ser. No.09/318,841, filed May 26, 1999, and Ser. No. 09/319,842, filed May 26,1999, all herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to engineering and managementsystems for the design of wireless systems and, more particularly, to amethod for displaying the performance of wireless systems in anyenvironment (e.g., buildings, floors within a building, campuses, withincities, an outdoor setting, etc.) using a three-dimensional (3-D)visualization method.

2. Description of the Prior Art

As wireless communication systems proliferate, radio frequency (RF)coverage within and around buildings, and radio signal penetration intoand out of buildings, has become a critical design issue for wirelessengineers who must design and deploy cellular telephone systems, pagingsystems, or new wireless technologies such as personal communicationsystems (PCS), wireless local area networks (WLAN), and localmulti-point distribution systems (LMDS). In addition, RP networksinvolving micromachinery, RF identification tags, and opticalcommunication links are of increasing interest. Designers are frequentlyrequested to determine if a radio transceiver location or base stationcell site can provide adequate, reliable service throughout a room, abuilding, an entire city, a campus, a shopping mall, or any otherenvironment. The costs of in-building and microcellular wirelesscommunication devices are diminishing while the workload for wirelesssystem design engineers and technicians to deploy such systems isincreasing sharply. Given these factors, rapid engineering design anddeployment methods accompanied by comprehensive system performancevisualization and analysis methods are vital to wireless communicationsystem designers.

Common to all wireless communication system designs is the desire tomaximize the performance and reliability of the system while minimizingthe deployment costs. Analyzing radio signal coverage and interferenceis of critical importance for a number of reasons. A design engineermust determine if an existing wireless system will provide sufficientsignal power throughout the desired service area. Alternatively,wireless engineers must determine whether local area coverage will beadequately supplemented by existing large scale outdoor wirelesssystems, or macrocells, or whether indoor wireless transceivers, orpicocells, must be added. The placement of these cells is critical fromboth a cost and performance standpoint. The design engineer must predicthow much interference can be expected from other wireless systems andwhere it will manifest itself within the environment.

Depending upon the design goals, the performance of a wirelesscommunication system may involve a combination of one or more factors.For example, the total area covered in adequate received signal strength(RSSI), the area covered in adequate data throughput levels, and thenumber of customers that can be serviced by the system are among thedeciding factors used by design engineers in planning the placement ofcommunication equipment comprising the wireless system. Thus, maximizingthe performance of a wireless system may involve the complex analysis ofmultiple, potentially unrelated factors. The ability to display theresults of such analysis in a manner easily interpretable by designengineers is invaluable in wireless system deployment. Three dimensional(3-D) visualization of wireless system operating parameters provides theuser with rapid assimilation of large data sets and their relation tothe physical environment. As wireless systems proliferate, these issuesmust be resolved quickly, easily, and inexpensively, in a systematic andrepeatable manner.

There are many computer aided design (CAD) products on the market thatcan be used to design a computerized model of an environment. WiSE™ fromLucent Technology, Inc., SignalPro™ from EDX, PLAnet™ by Mobile SystemsInternational, Inc., and TEMS from Ericsson are examples of CAD productsdeveloped to aid in the design of wireless communication systems.

Lucent Technology, Inc., offers WiSE™ as a design tool for wirelesscommunication systems. The WiSE system predicts the performance ofwireless communication systems based on a computer model of a givenenvironment using a deterministic radio coverage predictive techniqueknown as ray tracing.

EDX offers SignalPro™ as a design tool for wireless communicationsystems. The SignalPro system predicts the performance of wirelesscommunication systems based on a computer model of a given environmentusing a deterministic RF power predictive technique known as raytracing.

Mobile Systems International, Inc., offers PLAnet™ as a design tool forwireless communication systems. The PLAnet system predicts theperformance of macrocellular wireless communication systems based upon acomputer model of a given environment using statistical and empiricalpredictive techniques.

Ericsson Radio Quality Information Systems offers TEMS™ as a design andverification tool for wireless communication indoor coverage. The TEMSsystem predicts the performance of indoor wireless communication systemsbased on a building map with input base transceiver locations and usingempirical radio coverage models.

The above-mentioned design tools have aided wireless system designers byproviding facilities for predicting the performance of wirelesscommunication systems and displaying the results in the form of flat,two-dimensional grids of color or flat, two-dimensional contour regions.Such displays, although useful, are limited by their two-dimensionalnature in conveying all nuances of the wireless system performance. Forexample, slight variations in color present in a two-dimensional grid ofcolor, which may represent changes in wireless system performance thatneed to be accounted for, may be easily overlooked. Furthermore, aswireless systems proliferate, the ability to visually predict and designfor coverage and interference is of increasing value.

In addition, recent research efforts by AT&T Laboratories, BrooklynPolytechnic, and Virginia Tech are described in papers and technicalreports entitled:

S. Kim, B. J. Guarino, Jr., T. M. Willis III, V. Erceg, S. J. Fortune,R. A. Valenzuela, L. W. Thomas, J. Ling, and J. D. Moore, “RadioPropagation Measurements and Predictions Using Three-dimensional RayTracing in Urban Environments at 908 MHZ and 1.9 GHz, ” IEEETransactions on Vehicular Technology, vol. 48, no. 3, May 1999(hereinafter “Radio Propagation”);

L. Piazzi, H. L. Bertoni, “Achievable Accuracy of Site-SpecificPath-Loss Predictions in Residential Environments,” IEEE Transactions onVehicular Technology, vol. 48, no. 3, May 1999 (hereinafter“Site-Specific”);

G. Durgin, T. S. Rappaport, H. Xu, “Measurements and Models for RadioPath Loss and Penetration Loss In and Around Homes and Trees at 5.85GHz,” IEEE Transactions on Communications, vol. 46, no. 11, November1998;

T. S. Rappaport, M. P. Koushik, J. C. Liberti, C. Pendyala, and T. P.Subramanian, “Radio Propagation Prediction Techniques and Computer-AidedChannel Modeling for Embedded Wireless Microsystems,” ARPA AnnualReport, MPRG Technical Report MPRG-TR-94-12, Virginia Tech, July 1994;

T. S. Rappaport, M. P. Koushik, C. Carter, and M. Ahmed, “RadioPropagation Prediction Techniques and Computer-Aided Channel Modelingfor Embedded Wireless Microsystems,” MPRG Technical ReportMPRG-TR-95-08, Virginia Tech, July 1994;

T. S. Rappaport, M. P. Koushik, M. Ahmed, C. Carter, B. Newhall, and N.Zhang, “Use of Topographic Maps with Building Information to DetermineAntenna Placements and GPS Satellite Coverage for Radio Detection andTracking in Urban Environments,” MPRG Technical Report MPRG-TR-95-14,Virginia Tech, September 1995;

T. S. Rappaport, M. P. Koushik, M. Ahmed, C. Carter, B. Newhall, R.Skidmore, and N. Zhang, “Use of Topographic Maps with BuildingInformation to Determine Antenna Placement for Radio Detection andTracking in Urban Environments,” MPRG Technical Report MPRG-TR-95-19,Virginia Tech, November 1995; and

S. Sandhu, M. P. Koushik, and T. S. Rappaport, “Predicted Path Loss forRosslyn, Va., Second set of predictions for ORD Project on Site SpecificPropagation Prediction,” MPRG Technical Report MPRG-TR-95-03, VirginiaTech, March 1995.

The papers and technical reports are illustrative of thestate-of-the-art in site-specific radio wave propagation modeling. Whilemost of the above papers describe a comparison of measured versuspredicted RF signal coverage and present tabular or two dimensional(2-D) methods for representing and displaying predicted data, they donot report a comprehensive method for visualizing and analyzing wirelesssystem performance. The “Radio Propagation” and “Site-Specific” papersmake reference to 3-D modeling, but do not offer display methods orgraphical techniques to enable a user to visualize signal coverage orinterference in 3-D.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to facilitate thethree-dimensional, multi-colored display of predicted performanceresults for any type of wireless communication system.

It is another object of the present invention to provide a mechanism forviewing a three-dimensional display of predicted performance resultsfrom any angle, orientation, distance, or perspective.

It is another object of the present invention to provide a mechanism forviewing a three-dimensional display of predicted performance results andinteracting with the display in real-time to alter the current viewpointand perspective.

It is another object of the present invention to provide said display ofpredicted performance results overlaid on a three-dimensional databasethat may involve a plurality of building structures and the surroundingterrain, flora, climatic conditions, and additional static and dynamicobstacles (e.g., automobiles, people, filing cabinets, etc.).

It is another object of the present invention to provide a mechanism forcoloring, shading, and otherwise rendering a solid representation ofsaid three-dimensional display utilizing multiple colors andtransparency effects.

According to the present invention, a system is provided for allowing aRF system designer to dynamically model a wireless system electronicallyin any environment. The method includes the selection and placement ofmodels of various wireless system hardware components, such as antennas(point, omnidirectional, directional, leaky feeder, etc.), transceivers,amplifiers, cables, splitters, and the like, and allows the user tovisualize, in three-dimensions, the effects of their placement andmovement on overall system performance throughout the modeledenvironment. Thus, the placement of components can be refined andfine-tuned prior to actual implementation of a system to ensure that allrequired regions of the desired service area are blanketed with adequateRF coverage, data throughput, or system performance. Thethree-dimensional visualization of system performance provides RF systemdesigners with tremendous insight into the functioning of the modeledwireless communication system, and represents a marked improvement overprevious visualization techniques.

To accomplish the above, a 3-D model of the physical environment isstored as a CAD model in an electronic database. The physical,electrical, and aesthetic parameters attributed to the various parts ofthe environment such as walls, floors, foliage, buildings, hills, andother obstacles that affect radio waves are also stored in the database.A representation of the 3-D environment is displayed on a computerscreen for the designer to view. The designer may view the entireenvironment in simulated 3-D, zoom in on a particular area of interest,or dynamically alter the viewing location and perspective to create a“fly-through” effect. Using a mouse or other input positioning devicethe designer may select and view various communication hardware devicemodels from a series of pull-down menus. A variety of amplifiers,cables, connectors, and other hardware devices may be selected,positioned, and interconnected in a similar fashion by the designer toform representations of complete wireless communication systems.

A region of any shape or size may be selected anywhere within thedisplayed environment, or automatically selected based upon certaincriteria (e.g., selecting an entire building). The selected region isoverlaid with a grid containing vertices of selectable size, shape, andspacing to form a mesh or blanket. Each vertex corresponds to a singlepoint within the 3-D environment. Thereafter, a wireless systemperformance prediction model is run whereby the computer displays on thescreen at each vertex of the mesh the predicted RF values, for instance,received signal strength intensity (RSSI), network throughput, bit errorrate, frame error rate, signal-to-interference ratio (SIR), andsignal-to-noise ratio (SNR), provided by the communication system justdesigned. The display is such that the computer adjusts the elevationand/or coloring including characteristics such as saturation, hue,brightness, line type and width, transparency, surface texture, etc., ofeach vertex relative to the surrounding vertices to correspond to thecalculated RF values. The coloring and elevation may correspond to thesame calculated RF value or to different calculated RF values. Forexample, elevation may correspond to received signal strength intensity(RSSI), and color may correspond to signal-to-noise ratio (SNR), or anyother of a variety of calculated RF parameters. The user is able tospecify boundaries for this display in terms of selecting the range ofelevations, colors, or other aesthetic characteristics from which thevertices of the mesh are assigned. Alternatively, the system canautomatically select limits and ranges for the heights, colors, andother aesthetic characteristics. The result is a region of fluctuatingcolor and elevation representing the changing wireless systemperformance throughout different portions of the modeled 3-Denvironment. The region may be viewed overlaid with the 3-D environment.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, aspects and advantages will be betterunderstood from the following detailed description of a preferredembodiment of the invention with reference to the drawings, in which:

FIG. 1 is a flow diagram of the general method of the present invention;

FIG. 2 shows an example of a simplified layout of a floor plan of abuilding;

FIG. 3 shows a three-dimensional perspective of a building floor plan;

FIG. 4 shows an example region segmented into a grid that has beenselected by a RF designer for displaying wireless system performance;

FIG. 5 shows a region similar to that shown in FIG. 3 prior to thecalculation of wireless system performance and from a three-dimensionalperspective;

FIG. 6 shows the same region as in FIG. 3 following the calculation ofwireless system performance and is exemplary of the three-dimensionaldisplay of system performance from the present invention;

FIG. 7 shows the same region as in FIG. 6 following the user reducingrelative elevations of the vertices and thus altering the display;

FIG. 8 shows the same region as in FIG. 7 following the user shading thedisplay to produce an altered perspective of the performance results;and

FIG. 9 shows the same region as in FIG. 6 following the user changingthe view orientation to provide a different perspective of theperformance results;

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Using the present method, it is now possible to assess the performanceof a wireless communication system to a much higher level of precisionthan previously possible. The present method is a significant advanceover the prior art in the display of predicted performance of wirelesscommunication systems. The design of wireless communication systems isoften a very complex and arduous task, with a considerable amount ofeffort required to simply analyze the results of predicted performance.In the prior art, the only options available for displaying predictedcoverage areas involve the two-dimensional display of boundary contoursor colored grids overlaid with a two-dimensional representation of theenvironment. This is prohibitive to a design engineer in terms of theamount of information conveyed.

Referring to FIG. 1, there is shown a flow diagram according to thepresent invention. Before one can run an automated performancepredictive model on a desired environment, a 3-D electronicrepresentation of that environment must be created in function block 10.The preferred method for generating a 3-D environmental database isdisclosed in the co-pending application Ser. No. 09/318,841, filed onMay 26, 1999. The resulting definition utilizes a specially formattedvector database comprising lines and polygons that represent physicalobjects within the environment. The arrangement of lines and polygons inthe database corresponds to physical objects in the environment. Forexample, a line or other shape in the database could represent a wall, adoor, a tree, a building wall, or some other physical object in themodeled environment.

From the standpoint of radio wave propagation, eachobstruction/partition in an environment (i.e., each line or polygon inthe drawing) has electromagnetic properties that affect a radio wave.When a radio wave signal intersects a physical surface, it interactswith the electromagnetic properties of the surface. A certain percentageof the radio wave reflects off of the surface and continues along analtered trajectory; a certain percentage of the radio wave penetratesthrough the surface and continues along its course; a certain percentageof the radio wave is scattered once it strikes the surface, etc. Theelectromagnetic properties given to the obstruction/partition definesthis interaction, and thus defines the break down in percentages of theradio wave reacting in a given manner upon intersection. In terms of theenvironmental database, each obstruction/partition has severalparameters used to define its electromagnetic properties. For example,the attenuation factor of a partition determines the amount of powerlost by a radio signal that penetrates through it; the reflectivity of apartition determines the portion of the radio signal reflected from it;and the surface roughness of a partition determines the portion of theradio signal that is scattered upon intersection.

Once the 3-D environmental database has been constructed, the designeridentifies and specifies the location and type of all wirelesscommunication system equipment within the 3-D environmental database infunction block 20. This point-and-click process involves the userselecting the desired hardware component from a computer parts databaseand then visually positioning, orienting, and interconnecting varioushardware components within the 3-D environmental database to formcomplete wireless communication systems. The preferred embodiment of thecomputer parts database, referred to hereinafter as a parts listlibrary, is more fully described in co-pending application Ser. No.09/318,842, filed on May 26, 1999. The resulting interconnected networkof base station transceivers, cabling, connectors/splitters, amplifiers,antennas, and other RF hardware components (commonly known as a wirelessdistribution or antenna system) is preferably assembled using either adrag-and-drop or a pick-and-place technique and is graphically displayedoverlaid with the 3-D environmental database. Each component utilizeselectromechanical information available from the parts list library thatfully describes the component in terms of its physical operatingcharacteristics (e.g., the noise figure, frequency, radiationcharacteristics, etc.). This information is directly utilized during theprediction of wireless system performance metrics.

In function block 30, the designer selects the wireless communicationsystem performance predictive model to utilize. The preferred embodimentuses a number of methods to predict and optimize performance in awireless communication network. These include methods to incorporate andbuild upon performance prediction techniques such as those described inthe previously cited and following technical reports and papers:“Interactive Coverage Region and System Design Simulation for WirelessCommunication Systems in Multi-floored Indoor Environments: SMT Plus,”IEEE ICUPC'96 Proceedings, by R. Skidmore, T. Rappaport, and A. L.Abbott, and “SitePlanner 3.16 for Windows 95/98/NT User's Manual”,Wireless Valley Communications, Inc. 1999, all of which are herebyincorporated by reference. It would be apparent to one skilled in theart how to apply other wireless communication system performance modelsto this method.

Next, the designer selects the area within the 3-D environmentaldatabase in which to predict how the currently modeled wirelesscommunication systems will perform in function block 50. This is apoint-and-click process in which the designer uses the mouse or otherpointing device to designate the boundary of a region that encapsulatesthe area of interest within the 3-D environmental database. The regionidentified by the user represents a two-dimensional (2-D) plane withinthe 3-D environmental database. Once the region has been identified, thecomputer automatically segments the region into a grid of vertices(“mesh”). The designer is free to specify the size of each vertex andspacing between vertices of the mesh. Although the designated region isrectangular in the preferred embodiment of the invention, one skilled inthe art could see that the designated region could be of any shape. Thecomputer then calculates the selected wireless system performancepredictive model on the region.

Once the performance prediction is complete, the designer is free toconfigure the display of the results in function block 50. The displayedresults may be presented on a display screen, printed or otherwise 3-Drendered. The range of values to display and the color and otheraesthetic characteristics such as saturation, hue, brightness, line typeand width, transparency, surface texture, etc., to associate with eachvalue are selectable, or may be automatically adjusted by the system.For example, if displaying received signal strength intensity (RSSI),the user may select to only display those portions of the region havinga predicted RSSI within the range −50 dBm to −75 dBm, and may assignspecific colors to correspond to RSSI values within that range. Forexample, the user may assign the color red to represent a predicted RSSIvalue between −50 dBm and −55 dBm, green to represent a predicted RSSIvalue between −56 dBm and −60 dBm, etc. Thus, the region is displayed asa pattern of fluctuating colors where the color assigned to each vertexwithin the grid corresponds to a certain value for the predictedperformance metric.

In similar fashion, each vertex of the grid is repositioned verticallyin 3-D space. The elevation of each vertex directly corresponds to acertain value of predicted performance. In the preferred embodiment ofthe invention, the user specifies the maximum and minimum elevation toassign to vertices, and the computer automatically scales the elevationof each vertex according to its predicted performance value. Forexample, if the user selects a minimum height of 0.0 meters and amaximum height of 20.0 meters, and the predicted performance values forthe entire grid range from −50 dBm to −70 dBm for an RSSI prediction, ifa given vertex has a value of −60 dBm it will be assigned an elevationof 10.0 meters. All elevations are specified relative to the 3-Denvironmental database.

Any combination of elevation, color, and other aesthetic characteristicsmay be used to customize the display of predicted performance results.For example, signal-to-interference ratio (SIR) may be displayed asfluctuating elevation within the region while received signal strength(RSSI) is displayed by fluctuating colors. Data throughput may bedisplayed as varying colors while bit error rate (BER) is displayedusing differing line types. Any combination of elevation, color, andaesthetic characteristics may be associated with any combination ofpredicted performance result metric to produce the 3-D display.

The results of the performance prediction are displayed in functionblock 70 overlaid with or superimposed on the 3-D environmentaldatabase, allowing the user to analyze the performance of the currentwireless communication system design. The display can be furthercustomized in function block 80. The designer may reorient the viewingdirection and zoom factor of the display to achieve varying perspectivesof the predicted results. The results may be redisplayed in a variety offorms, including 3-D wireframe with hidden lines removed, 3-Dsemi-transparent, 3-D shaded or patterned, 3-D rendered, or 3-Dphoto-realistically rendered. The designer is free to interact with thedisplayed results in a variety of ways, including real-time panning andzooming to create a “fly-through” effect. The predicted performanceresults may be saved for later recovery and redisplay in function block85.

The designer may then decide to modify the electromechanical propertiesassigned to objects within the 3-D environmental database, modify thetype, orientation, or placement of components within the antennasystems, and/or add or remove wireless system hardware components infunction block 90. Performance predictions can then be repeated and theresults displayed as described above. Once the design is as desired,then the 3-D database contains all of the information necessary toprocure the necessary components for installing the wireless system. Thelocations of each component are clearly displayed, and a visual 3-Drepresentation can be viewed as a guide.

In addition, in function block 90, the various components of thecommunication system (i.e., transmitters, receivers, transceivers,antennas, cables, etc.) can be moved within the environment as well ascomponents of the environment itself in real time. In this manner, thedisplayed results superimposed on the displayed 3-D environment are alsoupdated in real time allowing the designer to immediately ascertain theeffect of the repositioning.

The preferred embodiment of the invention utilizes a 3-D environmentaldatabase containing information relevant to the prediction of wirelesssystem performance. This information includes but is not limited to thelocation, physical, electrical, and aesthetic properties of objectswithin the 3-D environment, where an object is any physical entity orlandscape feature, such as a tree, wall, door, person, climaticcondition, hill, etc.

Referring now to FIG. 2, there is shown a two-dimensional (2-D)simplified layout of a building floor plan. The method uses athree-dimensional (3-D) computer aided design (CAD) representation of abuilding, a collection of buildings, and/or the surrounding terrain andfoliage. However, for simplicity of illustration, a 2-D figure is used.The various physical objects within the environment such as externalwalls 101, internal walls 102, doors 103, and floors 104 are assignedappropriate physical, electrical, and aesthetic values such as height,attenuation or RF penetration loss, surface roughness, reflectivity,color, etc. The attenuation factor describes the amount of power a radiosignal loses upon striking a given object. The surface roughnessprovides information used to determine the portion of a radio signalthat is scattered and/or dissipated upon striking a given object. Thereflectivity provides information used to determine the portion of aradio signal that is reflected upon striking a given object. The valuesfor these and other parameters assigned to objects within the 3-Denvironmental database vary depending upon the type of object beingrepresented. For example, external walls 101 may be given a 15 dBattenuation value and have a very rough surface, whereas the interiorwalls 102 may only have a 3.2 dB attenuation loss.

The three-dimensional nature of the environmental database is shown inFIG. 3, which displays the same building layout as in FIG. 2 from adifferent orientation. Again, the physical objects within theenvironment such as external walls 101, internal walls 102, doors 103,and floors 104 are easily identifiable.

Estimated partition electrical properties may be extracted fromextensive propagation measurements already published, or the partitionparameters can be measured directly and optimized instantly using thepresent invention combined with those methods described in theco-pending application Ser. No. 09/221,985 filed on Dec. 29, 1998,entitled “System for Creating a Computer Model and Measurement Databaseof a Wireless Communication Network” filed by T. S. Rappaport and R. R.Skidmore. Once the desired physical and electrical properties arespecified for the objects in the environment, any desired number ofwireless system devices can be placed at any location in the 3-Denvironmental database, and performance predictions can be plotteddirectly onto the CAD drawing. The 3-D environmental database could bebuilt through any number of methods, the preferred being disclosed inthe concurrently filed co-pending application Ser. No. 09/318,841.

A base station transceiver 105 has been positioned and modeled withinthe 320 D environmental database. A length of cable 106 has beenconnected to the base station transceiver and extended throughout aportion of the database. A connector 107 has been attached to the end ofthe cable 108, and a length of radiating cable or leaky feeder 108 hasbeen run throughout the database. Because the method allows any type ofwireless system to be modeled, while analyzing the component andinstallation costs as disclosed in the concurrently filed, co-pendingapplication Ser. No. 09/318,842, “what-if” designs and scenarios can becarried out with minimum guess work and wasted time.

FIG. 3 depicts the three-dimensional perspective of a building floorplan. Referring to FIG. 3, there are several partitions within thebuilding structure, including exterior concrete walls 101 and interiorsheetrock walls 102.

FIG. 4 depicts the same environmental database as shown in FIG. 3. Thedesigner has specified the region within which the computer is topredict and display the performance of the modeled wirelesscommunication systems. The region 201, is identified with a mouse orother input device by pointing and clicking on locations 202 and 203within the 3-D environmental database. This identifies the oppositediagonals of a region within the database. Alternatively, the entiremodeled environment can be automatically selected and bounded to formthe region. The region is then segmented into a grid of vertices, knownas a mesh. The user may specify the spacing between each vertex 204 ofthe mesh. If the spacing is reduced, the number of vertices isautomatically adjusted to cover the region identified by the user. Thus,by reducing the spacing between the vertices, the user may control thenumber of vertices that form the mesh. Each vertex corresponds to alocation within the 3-D environmental database at which a performanceprediction will be carried out and displayed.

FIG. 5 depicts the identical environmental database as shown in FIG. 4from a three-dimensional perspective.

FIG. 6 depicts the identical environmental database as shown in FIG. 5following the prediction of performance for the wireless communicationsystem modeled in FIG. 2. FIG. 6 shows received signal strengthintensity (RSSI) as predicted within the modeled building environmentfor the base station transceiver 105 and the leaky feeder antenna 108 ofFIG. 2. In FIG. 6, the building environment 300 is displayed underneaththe predicted RSSI values. These values are calculated, for exampleusing models as described in co-pending application 09/318,840. The grid301 has assumed the form of a multi-colored region of fluctuatingheights. Each vertex 204 within the grid from FIG. 3 has had both itscolor and elevation altered to represent the value of RSSI predicted forthe point in 3-D space within the environmental database correspondingto the initial position of the vertex in FIG. 3. For example, in FIG. 6,vertices 302 with a relatively high elevation may be shown in redcorrespond to a higher level of predicted RSSI, while vertices 301 and303 with a relatively lower elevation corresponding to a lower level ofpredicted RSSI may be shown in blue, with intermediate heights shown inprogressive shades of red to blue or purples. The relative color,elevation, and other aesthetic characteristics of each vertexcorresponds to the RSSI value predicted to occur. Although, thedisplayed results are shown strictly in terms of RSSI, one skilled inthe art could see how this applies regardless of the performance metricselected. For example, in the present embodiment of the invention,similar displays could be generated for signal-to-interference ratios(SIR), signal-to-noise ratios (SNR), bit error rate (BER), frame errorrate (FER), frame resolution per second, traffic, capacity, and datathroughput.

FIG. 7 depicts the identical results as shown in FIG. 6 with theexception that the user has altered the relative heights assigned to thevertices. The visual effect is to overlap the predicted performanceresults 401 with the 3-D environmental database 402. Such a perspectiveenables the designer to instantly recognize areas within the environmentwhere there is sufficient system performance 403 and areas where thereis inadequate system performance 404 simply by noting the color and/orrelative height of the predicted results.

FIG. 8 depicts the identical results as shown in FIG. 7 with theexception that the user has shaded the environment produce a morerealistic visual representation.

FIG. 9 depicts the identical results as shown in FIG. 7 with theexception that the user has altered the viewing orientation to achieve adifferent perspective of the predicted performance results.

While the invention has been described in terms of a single preferredembodiment, those skilled in the art will recognize that the inventioncan be practiced with modification within the spirit and scope of theappended claims. For example, this invention may not be limited just towireless communication systems, but may be used to present any type ofelectromagnetic characteristics superimposed on any simulatedthree-dimensional environment. For example, the invention would findapplication in the next generation field of micromachines andnanomachines or micro-electrical-mechanical machines (MEMS). Thesemachines are extremely small yet highly sophisticated functionalelements that allow them to perform complicated tasks in hard-to-accesslocations, such as inside the human body, in plumbing, in jet engines,etc. It will be necessary to both wirelessly communicate with thesemachines as well as wirelessly provide power for these machines, such asin the form of RF pulses, infrared (IR) light or any other form ofelectromagnetic medium. The present invention would therefore facilitatethe modeling and presentation of this or any other wirelesselectromagnetic system.

We claim:
 1. A computer implemented method for displaying a simulatedperformance characteristic for a wireless communication system,comprising the steps of: modeling a three-dimensional environment;modeling a wireless communication system in said three-dimensionalenvironment; generating a computer simulation of at least oneperformance characteristic for said wireless communication systemoperating in said three-dimensional environment; displaying saidthree-dimensional environment; and displaying said at least oneperformance characteristic as a three-dimensional representation offluctuating elevations superimposed on said displayed three-dimensionalenvironment, wherein said three-dimensional representation comprises amesh of fluctuating elevations, wherein a height of said fluctuatingelevations corresponds to a value of said at least one performancecharacteristic.
 2. A computer implemented method for displaying asimulated performance characteristic for a wireless communication systemas recited in claim 1 further comprising the step of selecting only aportion of said three-dimensional environment to be displayed.
 3. Acomputer implemented method for displaying a simulated performancecharacteristic for a wireless communication system as recited in claim1, wherein said three-dimensional environment comprises at least onebuilding.
 4. A computer implemented method for displaying a simulatedperformance characteristic for a wireless communication system asrecited in claim 1, wherein said three-dimensional environment comprisesany of buildings, furniture, landscaping, terrain, climatic conditions,and obstacles.
 5. A computer implemented method for displaying asimulated performance characteristic for a wireless communication systemas recited in claim 1, wherein said at least one performancecharacteristic comprises any of radio signal strength intensity (RSSI),network throughput, bit error rate, frame error rate,signal-to-interference ratio (SIR), and signal-to-noise ratio (SNR). 6.A computer implemented method for displaying a simulated performancecharacteristic for a wireless communication system as recited in claim1, further comprising the step of moving a displayed three-dimensionalregion to create a fly-through effect.
 7. A computer program fordisplaying simulated radio frequency (RF) characteristics for a wirelesscommunication system, comprising the steps of: modeling a wirelesscommunication system in a simulated three-dimensional environment;calculating RF characteristics for said wireless communication system;and displaying said RF characteristics as a three-dimensionalrepresentation of fluctuating elevations superimposed on saidthree-dimensional environment, wherein said three-dimensionalrepresentation of fluctuating elevations comprises a mesh, wherein aheight of said mesh at any given point corresponds to a value of said RFcharacteristics at said point.
 8. A computer program for displayingsimulated radio frequency (RF) characteristics for a wirelesscommunication system as recited in claim 7, further comprising the stepof color coding said mesh according to a value of said RFcharacteristics.
 9. A computer program for displaying simulated radiofrequency (RF) characteristics for a wireless communication system asrecited in claim 7 wherein said RF characteristics are selected from thegroup consisting of radio signal strength intensity (RSSI), networkthroughput, bit error rate, frame error rate, signal-to-interferenceratio (SIR), and signal-to-noise ratio (SNR).
 10. A computer program fordisplaying simulated radio frequency (RF) characteristics for a wirelesscommunication system as recited in claim 7 wherein saidthree-dimensional environment comprise s at least one building.
 11. Acomputer program for displaying simulated radio frequency (RF)characteristics for a wireless communication system as recited in claim7 wherein said three-dimensional environment comprises any of buildings,furniture, landscaping, terrain, climatic conditions, and obstacles. 12.A computer program for displaying simulated radio frequency (RF)characteristics for a wireless communication system as recited in claim7, further comprising the step of moving a displayed three-dimensionalrepresentation of fluctuating elevations to create a fly-through effect.13. A method for presenting simulated radio frequency (RF)characteristics for a wireless communication system, comprising;creating a database of parameters comprising a three-dimensionalenvironment; positioning representations of hardware device componentswithin said environment to form a wireless communication system; runninga prediction model of the wireless communication system to predict RFcharacteristics at points within said environment; configuring said RFcharacteristics in terms of relative elevations on a mesh; presentingsaid mesh superimposed on said three-dimensional environment, wherein arelative height of said mesh at any given point in saidthree-dimensional environment corresponds to said RF characteristics atthat point.
 14. A method for presenting simulated radio frequency (RF)characteristics for a wireless communication system as recited in claim13 further comprising the step of configuring said RF characteristics interms of color on said mesh.
 15. A method for presenting simulatedelectromagnetic radio frequency (RF) characteristics for a wirelesscommunication system as recited in claim 13 wherein said database ofparameters comprising said three-dimensional environment includes any ofbuildings, furniture, landscaping, terrain, climatic conditions, andobstacles and said hardware device parameters includes any of antennas,receivers, transmitters, cables, amplifiers and splitters.
 16. A methodfor presenting simulated radio frequency (RF) characteristics for awireless communication system as recited in claim 13, wherein said RFcharacteristics comprise any of radio signal strength intensity (RSSI),network throughput, bit error rate, frame error rate,signal-to-interference ratio (SIR), and signal-to-noise ratio (SNR). 17.A method for presenting simulated radio frequency (RF) characteristicsfor a wireless communication system as recited in claim 13, wherein saidmesh comprises a plurality of wireframe connected vertices.
 18. A methodfor presenting simulated radio frequency (RF) characteristics for awireless communication system, comprising: creating a database ofenvironmental elements comprising a three-dimensional environment;positioning representations of hardware device components within saidthree-dimensional environment to form a wireless communication system;repositioning at least one of a group consisting of an environmentalelement and a hardware device component which are selected from saidenvironmental elements and said hardware device components; runningprediction models for said wireless communication system to predict RFcharacteristics within said three-dimensional environment; andpresenting said predicted RF characteristics as a three-dimensionalrepresentation superimposed on said three-dimensional environment,wherein said three dimensional representation changes in real time assaid at least one of said group consisting of an environmental elementand a hardware device component selected from said environmentalelements and said hardware device components are repositioned.
 19. Amethod for presenting simulated electromagnetic characteristics in asimulated three-dimensional environment, comprising the steps of:modeling a wireless electromagnetic system in a simulatedthree-dimensional environment; calculating electromagneticcharacteristics for said wireless electromagnetic system; and presentingsaid calculated electromagnetic characteristics as a three-dimensionalrepresentation of fluctuating elevations superimposed on saidthree-dimensional environment.
 20. A method for presenting simulatedelectromagnetic characteristics in a simulated three-dimensionalenvironment as recited in claim 19 wherein said three-dimensionalrepresentation comprises at least one of fluctuating elevations andcolors.